Plural blade strip magazine with blade strip tensioning mechanism

ABSTRACT

A safety razor blade magazine comprises an elongated blade strip having a portion adjacent one end thereof wound upon itself to form a storage coil, rotatable take-up reels to which the other end of the blade strip is secured and upon which it can be wound to form a take-up coil. The strip having a path of travel from the storage coil to the take-up coil, and including a section along which a length of blade strip is exposed for shaving use. The length of the blade strip exposed for shaving is supported at its ends only, the intermediate portion thereof being left otherwise free and unsupported. The magazine further including tensioning mechanism for holding the exposed length of the blade strip under longitudinal tension sufficient to give it the degree of rigidity required for use in shaving. For shaving use, the magazine may be attached to a suitable handle.

United States Patent Pomfret et al.

PLURAL BLADE STRIP MAGAZINE WITH BLADE STRIP TENSIONING MECHANISM Inventors: Edward E. Pomfret, Newbury;

Norman C. Welsh, Bradfield, both of England The Gillette Company, Boston, Mass.

Filed: Oct. 29, 1973 Appl. No.: 410,394

Assignee:

Foreign Application Priority Data on. 30. 1972 United Kingdom.... 50 002/72 References Cited UNITED STATES PATENTS 6/1917 Sterrick 30/52 X 7/1966 Nissen 30/3465 l/l97l Ferraro 30/3465 X 3,597,840 8/1971 Forehand 30/401 Primary ExaminerAl Lawrence Smith Assistant ExaminerGary L. Smith [57] ABSTRACT A safety razor blade magazine comprises an elongated blade strip having a portion adjacent one end thereof wound upon itself to form a storage coil, rotatable take-up reels to which the other end of the blade strip is secured and upon which it can be wound to form a take-up coil. The strip having a path of travel from the storage coil to the take-up coil, and including a section along which a length of blade strip is exposed for shaving use. The length of the blade strip exposed for shaving is supported at its ends only, the intermediate portion thereof being left otherwise free and unsupported. The magazine further including tensioning mechanism for holding the exposed length of the blade strip under longitudinal tension sufficient to give it the degree of rigidity required for use in shaving. For shaving use, the magazine may be attached to a suitable handle.

5 Claims, 2 Drawing Figures A PLURAL BLADE STRIP MAGAZINE WITH BLADE STRIP TENSIONING MECHANISM This invention relates to safety razors of the band or ribbon type, that is razors making use of a blade strip of substantial length only a small part of which is exposed for use at any one time, the remainder of the strip being wound into storage and takeup coils, the strip being advanced from one coil to the other whenever it is desired to bring a fresh length of the strip into position for use.

In the known razors of this type the length of blade strip which is in position for use is supported throughout its length upon a guide surface and is held firmly in engagement with this surface either by clamping means or by applying a slight tension to the strip.

In accordance with a feature of the present invention (the precise scope of which is defined in the appended claims) the portion of the blade strip which is exposed for use is supported at its ends only, the intermediate portion being left otherwise free and unsupported and being given sufficient rigidity by being held under substantial longitudinal tension. The thickness and width of the blade strip and the tensioning force applied to it may all be varied within fairly wide limits, these three parameters being to some extent at least interdependent.

The blade strip may be made from sheet metal stock of any thickness within the range of thicknesses employed in commercially available safety razor blades, that is from about 0.0015 inch up to about 0.010 inch. While satisfactory results can be obtained with a blade strip 0.125 inch in width it is generally advantageous to employ a narrower strip having a width of 0.100 inch or less, a width in the range 0.030 to 0.060 inch being preferred. In general, the narrower the blade strip the greater is the tensional force required to hold the unclamped operative portion of the strip (which conveniently has a length of some 1.25 inch) sufficiently rigid to constitute a satisfactory shaving instrument. The forces imposed on the blade strip during shaving tend to twist the strip about its longitudinal axis so as to increase the angle at which the cutting edge engages the skin and this angle should not be allowed to increase beyond a maximum of about 35. By way of example the blade may beset initially at an angle of 22 and so tensioned that in normal use the angle will not increase beyond 27. The applied tension leaves the blade with some degree of lateral flexibility and this appears to be advantageous as allowing the blade to conform to some degree with the shape of the surface being shaved. With a relatively wide blade a tension of as little as /zlb weight may be sufficient to hold the blade against twisting but with the preferred narrower blades greater ten sion is necessary. However, the narrower and thinner the blade strip, the less is the maximum force which it can withstand. A blade strip of stainless steel measuring 0.040 inch in width and 0.004 inch in thickness, for example, will snap under a tensional force of about 35 lb weight and to provide an adequate margin of safety the tensional force applied preferably does not exceed about half the breaking stress.

The preferred form of safety razor blade magazine in accordance with the present invention includes operating means so constructed and arranged that a single manual operating movement is effective to cause automatically and successively: unlocking of a reel on which the storage coil is mounted, to permit rotation thereof; rotation of the take-up means to wind blade strip off the storage reel and on to the take-up coil to an extent sufficient to bring a fresh length of the strip into operative position; relocking of the storage reel to prevent further rotation thereof; and further rotation of the take-up reel sufficient to apply a controlled tension to the operative length of the blade strip.

By way of illustrative example, the accompanying drawings show a replaceable magazine for a ribbon type safety razor, the magazine being in use removably mounted upon a handle (not shown) to constitute the complete razor. The particular magazine illustrated is designed to accommodate two blade strips, each 0.040 inch wide, and of a length sufficient to provide in each strip 25 successive shaving lengths, each 1.5 inch in length. The two blade strips are sharpened along one edge only and are arranged in tandem, their cutting edges acting in succession on the surface to be shaved. In the drawings:

FIG. 1 is a part sectional front view of the magazine, and

FIG. 2 is a cross-section therethrough.

The magazine illustrated comprises a casing, indicated generally by the reference numeral 1, constructed from moulded plastics material. This casing is preferably reinforced by a metal pressing 2 to withstand the forces imposed by the blade tensioning system. Within the casing is disposed a storage reel 3 rotatably supported upon a hub 4, carried by the casing. Also disposed within the casing are two take-up reels 5, 6 disposed coaxially one behind the other and mounted for rotation about an axis parallel to but spaced laterally from that of the storage reel 3. Two blade strips 7, 8 each have one end anchored (as at 9) to the storage reel, on which the greater part of the blade strips is initially wound up. From the storage reel the blade strips 7, 8 extend over guide shoulders 11, 12 formed on the casing adjacent one end thereof and hence in unsupported lengths to similar guide shoulders 13, 14 adjacent the opposite end of the casing, the other ends of the blade strips being anchored (as at 10) to the respective take-up reels 5, 6. The straight lengths of the blade strips which are exposed between the pairs of shoulders 11, 13 and 12, 14 lie in parallel planes with their sharpened edges directed forwardly (downwardly in FIG. 2) and are set at the required shaving angle to the surfaces 15 and 16 of the casing which respectively engage the skin ahead of and behind the two tandem cutting edges and constitute the guard and cap surface for ensuring that the blades are positioned in the required relationship to the surface to be shaved.

In order to ensure correct location of the blade strips and to protect the sharpened edges of the blades from possible damage by contact with other parts of the magazine, the core of the storage reel 3 and the shoulders ll, 12, 13 and 14 are given a frusto-conical shape, tapering at a small angle towards the rear, so that the tension applied to the blade strip tends to shift the latter rearwardly on these surfaces bringing their blunt rear edges against locating flanges. The core of the rear take-up reel 6 is similarly tapered towards the rear, ensuring that the blunt rear edge of blade strip 8 is held close against the radially projecting flange of reel 6 as the strip is wound up on the reel. The core of the front take-up reel 5, however, tapers forwardly, so that the sharpened front edge of blade strip 7 (which has been used and can be damaged with impunity) is held close relative to the shaft. At its rear end the shaft is formed to be keyedly received in a recess 18 in a rotary operating member 32 carried on the razor handle 33, this member also making keyed engagement with a cap 19 rotatably mounted on the razor handle 33 and connected to it through a unidirectional spring clutch 20, which permits rotation in one direction only of the operating member and thus of shaft 17. The spring clutch comprises a coil spring 20 located around the boss of the cap 19, one end of the spring being located in the razor handle 33. The spring is wound with a left-hand helix (FIG. 2) so that movement of the cap 19 in a clockwise direction opens the spring coils allowing the cap and, thus, the shaft 17, to turn. Movement of the cap in an anti-clockwise direction closes the spring coils on to the boss of the cap and prevents rotation of the cap and, thus the shaft 17. Forwardly of reel 5 and rearwardly of reel 6 squared portions of shaft 17 engage within square apertures in drive discs 21, 22 which consequently rotate with the shaft. Each of these drive discs is formed with a pair of diametrically opposite apertures, extending through the thickness of the disc, each aperture containing a rubber bush 23. Pins 24 carried by the reels 5, 6 extend into the bores of the bushes 23 carried by the respective drive discs 21, 22.

The peripheral surface of rear drive disc 22 is formed with a cam projection 25 (FIG. 1) adapted to engage one end of a locking member 26, mounted for sliding movement laterally of the casing, the other end of this member being formed with teeth adapted to engage on the periphery of a disc 27 which is fast to the storage spool 2.

Front drive disc 21 carries an eccentric boss 28 which engages rotatably within a circular aperture in a gear wheel 29 having 25 teeth. Gear wheel 29 meshes with an internally toothed gear ring 30 fast to the casing and having 26 teeth. A window 31 in the front wall of the casing allows observation of markings on the face of gear wheel 29.

While the razor is in use, the storage reel 3 is held against rotation by the engagement of locking member 26 with disc 27, as shown in FIG. 1, the locking member being held in engaging position by the cam projection 25. When it is desired to bring a fresh length of the blade strip into position for use, shaft 17 is rotated through one complete revolution, and an indexing device (not shown) is preferably provided to assist in ensuring that the shaft is turned through exactly one revolution at each operation. The initial movement of the shaft (during which bushes 23 yield and prevent the application of undue tension to the blade strips) carries cam projection 25 clear of locking member 26, allowing the latter to move clear of disc 27, so that the storage reel 3 is free to rotate. Further rotation of shaft 17 rotates the drive discs 21, 22 and thus (through bushes 23 and pins 24) the take-up reels 5, 6, which accordingly wind on appropriate lengths of the blade strips 7, 8. Towards the end of the revolution, cam projection 25 again engages locking member 26 and returns it into engagement with disc 27, preventing further rotation of storage reel 3. The continued rotation of shaft 17 and drive discs 21, 22 to complete one revolution thereof produces further rotation of takeup reels 5, 6 and applies tension to the blade strips 7, 8, the compressible bushes 23 yielding progressively as the tension in each blade strip increases and ensuring that each blade strip is individually and independently subjected to the desired tension, leaving the newly positioned lengths of the blade strips in condition for use. The rotation of the eccentric boss 28 with shaft 17 causes gear wheel 29 to roll around the inner periphery of gear ring 30 and owing to the difference between the numbers of teeth on these two members this movement results in gear wheel 29 being rotated through one twenty-fifth of a revolution, thus changing the marking on the gear wheel which is visible through window 31 and which serves to indicate the length of blade strip which has been used or which remains unused.

The magazine described and illustrated is intended for use with a handle of the character disclosed in the specifications of our prior British Pat. Nos. 1,143,320, 1,199,121 and 1,225,060. The magazine is preferably so constructed as to be interchangeable with the magazines disclosed in those specifications, many of the features of which may be employed also in magazines in accordance with the present invention. However, magazines in accordance with the invention can alternatively be constructed for use with handles of other kinds and may constitute an integral part of complete razors.

What is claimed is:

l. A safety razor blade magazine comprising two elongated blade strips, each having the portion adjacent one end thereof wound upon itself to form a storage coil, rotatable take-up means to which the other end of each blade strip is secured and upon which it can be wound to form a take-up coil, means defining a path of travel for the strips from the storage coil to the takeup coil, said path including a section along which a length of each blade strip is exposed for shaving use, the lengths of the respective blade strips which are exposed for use lying parallel to one another in such relationship that when used for shaving their cutting edges will follow one another over the surface to be shaved, said path-defining means being such that the said length of the blade strip is supported at its ends only, the intermediate portion thereof being left otherwise free and unsupported, means for holding the said lengths of the blade strips under longitudinal tension sufficient to give it the degree of rigidity required for use in shaving, and common means for rotating the take-up means of both blade strips.

2. A-magazine in accordance with claim 1, wherein holding means include releasable locking means operable to prevent unwinding of the blade strip from the storage coil for travel along said path, rotation of said take-up means after said locking means has been operated to prevent unwinding of the blade strip from the storage coil being effective to apply the required tension to the said length of the blade strip.

3. A magazine in accordance with claim 2 and including a rotatably mounted storage reel on which the storage coil is carried, the locking means being releasable to permit rotation of the storage reel in the direction of unwinding of the storage coil.

4. A safety razor blade magazine comprising an elongated blade strip having the portion adjacent one end thereof wound upon itself to form a storage coil, rotatable take-up means to which the other end of the blade strip is secured and upon which it can be wound to form a take-up coil, means defining a path of travel for the strip from the storage coil to the take-up coil, said path including a section along which a length of the blade strip is exposed for shaving use, said pathdefining means being such that the said length of the blade strip is supported at its ends only, the intermediate portion thereof being left otherwise free and unsupported, releasable locking means for holding the said length of the blade strip under longitudinal tension sufficient to give it the degree of rigidity required for use in shaving, said releasable locking means being operable to prevent unwinding of the blade strip from the storage coil for travel along said path, rotation of said take-up means after said locking means has been operated to prevent unwinding of the blade strip from the storage coil being effective to apply the required tension to the said length of the blade strip, operating means so constructed and arranged that a single manual operating movement is effective to cause release of the locking means; rotation of the take-up means to wind the blade strip off the storage coil, along the said path, and into the take-up coil to the extent required to bring a fresh length of the blade strip onto said section of the path; reengagement of the locking means; and.

further rotation of the take-up means to the extent required to apply the desired tension to the said fresh length of the blade strip, and spring means interposed between the operating means and the take-up means, continued movement of the operating means after reengagement of the locking means being effective to stress the spring means so that the latter resiliently biasses the take-up means to rotate in the direction of take-up of the strip.

5. A magazine in accordance with claim 4 and including a second blade strip, each arranged as defined, the lengths of the respective blade strips which are exposed for use lying parallel to one another in such relationship that when used for shaving their cutting edges will follow one another over the surface to be shaved, and common means for rotating the takeup means of both blade strips. 

1. A safety razor blade magazine comprising two elongated blade strips, each having the portion adjacent one end thereof wound upon itself to form a storage coil, rotatable take-up means to which the other end of each blade strip is secured and upon which it can be wound to form a take-up coil, means defining a path of travel for the strips from the storage coil to the take-up coil, said path including a section along which a length of each blade strip is exposed for shaving use, the lengths of the respective blade strips which are exposed for use lying parallel to one another in such relationship that when used for shaving their cutting edges will follow one another over the surface to be shaved, said path-defining means being such that the said length of the blade strip is supported at its ends only, the intermediate portion thereof being left otherwise free and unsupported, means for holding the said lengths of the blade strips under longitudinal tension sufficient to give it the degree of rigidity required for use in shaving, and common means for rotating the take-up means of both blade strips.
 2. A magazine in accordance with claim 1, wherein holding means include releasable locking means operable to prevent unwinding of the blade strip from the storage coil for travel along said path, rotation of said take-up means after said locking means has been operated to prevent unwinding of the blade strip from the storage coil being effective to apply the required tension to the said length of the blade strip.
 3. A magazine in accordance with claim 2 and including a rotatably mounted storage reel on which the storage coil is carried, the locking means being releasable to permit rotation of the storage reel in the direction of unwinding of the storage coil.
 4. A safety razor blade magazine comprising an elongated blade strip having the portion adjacent one end thereof wound upon itself to form a storage coil, rotatable take-up means to which the other end of the blade strip is secured and upon which it can be wound to form a take-up coil, means defining a path of travel for the strip from the storage coil to the take-up coil, said path including a section along which a length of the blade strip is exposed for shaving use, said path-defining means being such that the said length of the blade strip is supported at its ends only, the intermediate portion thereof being left otherwise free and unSupported, releasable locking means for holding the said length of the blade strip under longitudinal tension sufficient to give it the degree of rigidity required for use in shaving, said releasable locking means being operable to prevent unwinding of the blade strip from the storage coil for travel along said path, rotation of said take-up means after said locking means has been operated to prevent unwinding of the blade strip from the storage coil being effective to apply the required tension to the said length of the blade strip, operating means so constructed and arranged that a single manual operating movement is effective to cause release of the locking means; rotation of the take-up means to wind the blade strip off the storage coil, along the said path, and into the take-up coil to the extent required to bring a fresh length of the blade strip onto said section of the path; reengagement of the locking means; and further rotation of the take-up means to the extent required to apply the desired tension to the said fresh length of the blade strip, and spring means interposed between the operating means and the take-up means, continued movement of the operating means after reengagement of the locking means being effective to stress the spring means so that the latter resiliently biasses the take-up means to rotate in the direction of take-up of the strip.
 5. A magazine in accordance with claim 4 and including a second blade strip, each arranged as defined, the lengths of the respective blade strips which are exposed for use lying parallel to one another in such relationship that when used for shaving their cutting edges will follow one another over the surface to be shaved, and common means for rotating the takeup means of both blade strips. 